1. Field of the Invention
The present invention relates to the intravenous injection of liquids into the body. More particularly, the invention relates to an improved apparatus for trapping sediment and gaseous bubbles for preventing undesirable materials from entering the body with the injected liquid.
2. Prior Art
Gas and solid gas traps are commonly used in the United States and throughout the world for trapping gas bubbles and sediment to prevent them to enter intravenous injection fluid lines. Most such apparatus and systems are either bulky in size, complex to manufacture and some allow the reentry of gas bubbles or sediment into the intravenous (IV) line under a sudden move of patient""s limb. Such current devices also falter when employed in the field under rough handling and transport conditions such as during a disaster, a battlefield or when administering transfusion in a helicopter.
It is also known that there exist a common hazard associated with the injection of fluid into the veins of a human or animal when gas bubbles and sediment enter the body. Commonly, when air bubbles are observed in an intravenous transparent tubing line, the injection needle must be withdrawn immediately from the vein, the supply line purged of the air bubbles, and the needle reinserted into the vein to continue the injection. This operation is time-consuming and often painful and dangerous to the patient. If air bubbles enter the vein with the injection liquid, an air embolus is produced, usually resulting in severe pain to the patient, and if allowed to continue even for several seconds, the patient may receive a dangerous or fatal amount of air. Even though a constant watch is maintained, it is not infrequent for a severe or fatal air embolus to develop within a matter of several seconds. The repeated purging of air from the tubing which connects the injection needle to the liquid supply results in a loss of valuable medicinal material, and as usually performed, the medicinal liquid is sprayed over the floor and on equipment in the room where the patient is being treated.
In the prior art, gas and solid trap devices for use in blood transfusion or for other intravenous injection are provided at the wall portion in the neighborhood of a projection or needle sometimes using filters or other manner of entrapment.
Although various devices have long been known for intravenous injecting medicinal liquids into the body, the most widely practiced process is known as the gravity-flow method. In that method a hypodermic needle is connected by rubber tubing to a vessel containing the fluid to be injected. The vessel, which is usually provided with a flow-regulating cock, is suspended above the patient, and after the regulating cock, tubing and needle are completely purged of air, the needle is properly inserted into the patient""s vein and the solution is allowed to flow by gravity into the vein.
There are a number of approaches advanced in prior art, however such prior art still leave problems regarding the size of apparatus, the ease of manufacture of devices which ultimately affects the cost of the apparatus and most importantly the heath risk involved with the reentry of bubbles and sediment into the intravenous injection fluid. However, prior art addresses only partially these issues leaving a constant hazard to users of such devices.
U.S. Pat. No. 2,597,699, Bauer, teaches an air and sediment trap comprised of a cylindrical tube with a bulging space that must be kept continuously in a vertical position. Bauer""s device is cumbersome in size and causes a major health risk factor if the bulging space is turned upside-down or otherwise displaced in the wrong direction.
U.S. Pat. No. 3,834,124, Ichikawa, teaches a gas trap device with longitudinal extending U-shaped passageway for intravenous use. In this degassing device the rising of bubble or gas is prevented by the axial flow of a transfusion liquid. However, the removal of gas or bubbles from a transfusion liquid is not necessarily complete in such devices. In addition, The device is difficult to manufacture and has the same disadvantage than Bauer, it fails to prevent sediment and air bubbles to reenter the intravenous line if positioned anywhere but upright.
U.S. Pat. Nos. 5,312,352 and 5,439,448, Leschinsky et al., teach a system and method for connecting two fluid carrying tubes, one having a bubble elimination port. The bubble elimination port closes to the fluid circuit after tube connections are done and thus does not provide a trap for trapping incoming gas bubbles or solids on an ongoing basis.
In most above mentioned devices, drawbacks are encountered that sudden changes in position of the patient""s limb cause air bubbles and sediment to be entrained back into the line and ultimately to the patient. As such, there exists a need for an easily and inexpensively manufactured apparatus, which can be safely used to trap sediment and gas bubbles in fluids flowing in intravenous injection lines. Furthermore such an apparatus should operate in an infinite number of apparatus tilt angles and use conventionally used intravenous tubing apparatus. Such a device should also be easily used by employees without the need for extensive training.
In summary, the applicant""s device overcomes drawbacks of the prior art by providing a novel apparatus for the trapping of gaseous bubbles and solid particles entrained in the fluids circulating in fluid-tight conduits of generally all sizes used in intravenous supply to humans and animals. The device when inserted into the conduit between the fluid source and patient, traps gas bubbles and solid particles entrained in fluids flowing in intravenous tubes in particular.
In one aspect, the present invention relates to an apparatus for trapping gas bubbles and foreign solid particles in a continuous, fluid-tight circuit. The preferred embodiment of the device generally includes a longitudinal revolved chamber having one or preferably a plurality of bulging walls, a first inlet end having inlet orifice means communicating at one end with internal bulging chamber walls. A second exit at the opposite end having second outlet orifice provides a means for communication with the interior of a cavity having internal opposing bulging chamber walls using a rigid tube or nozzle axially disposed relative said chamber having inlet aperture projecting into second outlet orifice at a midpoint into said bulging chamber.
Incoming low density bubbles entrained in IV fluid once entering the chamber from any angle, surge instantly toward fluid surface pushed by buoyancy forces generated by the density differential between the denser IV fluid and the low density bubbles, while heavier solid particles sediment at bottom. Such natural forces push continuously on the bubbles and solids in a direction away from the center of liquid flowing through said longitudinal chamber. The bubbles forcing their way toward the outer wall of the chamber creates favorable conditions for a bubble-free, solid-free IV liquid to exit through the aperture located at the end of the centrally located outlet nozzle inside the chamber in order to enter a patient""s body.
According to a further important feature of the present invention, the aperture inside diameter of a central outlet nozzle is kept small in the range of 0.5-2.5 mm, preferable 2 mm to prevent entrainment of bubbles of generally bigger diameter to squeeze themselves out of this novel trap. Depending on the density and viscosity of each intravenous fluid, the aperture diameter of outlet tube may also be provided with a cross-hair partition ring reducing further the size of said diameter aperture, thus impeding further any possibility for bubbles to exit the trap.
The cooperative attachment to the trap may be frictionally engaged, threadably engaged or engaged by male-female coupling adapter or otherwise cooperatively engaged or use a combination thereof.
It is an object of this invention to provide an easily used, sterile and disposable free-bubble apparatus to trap gas bubbles and solid particles entrained in fluids flowing in intravenous injection lines no matter what angle the device is placed.
Another object of this invention is to provide an easily manufactured and operated apparatus for the trapping of solid particles and gaseous bubbles entrained in intravenous injection lines.
A further object of this invention is to provide a very cost-effective and efficient method of trapping gas bubbles and solid foreign particles from circulating fluids in general and from flowing liquids in intravenous injection lines in particular.
An additional object of this invention is to provide a gas bubble and solid particle trap that is easily operable requiring no adjustment, little skill, no training or dexterity.
Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.